No announcement yet.

Selected gear indication for the GDJ's 6-speed transmission using OBDII

  • Filter
  • Time
  • Show
Clear All
new posts

  • Selected gear indication for the GDJ's 6-speed transmission using OBDII

    I bought my Jan 2017 Prado GX (MY2016) to tow our camper trailer on periodic trips when the demands of my business allow. My previous vehicle was a Kluger which was a little underrated to tow the camper. I had developed a CAN bus interface for the Kluger to monitor the status of the vehicle's doors: due to the situation of our house, the car port is exposed to the street. The CAN-bus door state monitor is connected via a wireless link to our living area, indicating the state of the car's doors (open/closed/locked/unlocked).

    Since we tow a lot, it would be nice to know what gear is engaged, when the torque converter is locked and also monitor the transmission temperatures. Many members here would be aware that the Aisin-Warner AC60F automatic transmission is under full electronic control: gone is the separate transmission ECU of the KDJ. The GDJ150R's 1GD engine and 6-speed transmission are closely managed by a single unit. Since it's all electronic, it should be easy to extract what gear is currently engaged as well as TC lockup: easy, right? I wish! I had scoured the internet, including forums around the world. Many people want this real-time elusive data but I couldn't find information on it published anywhere.

    As I mentioned earlier I had already designed and built my own CAN bus interface for my Toyotas. Not an easy task: there is a lot to be learned! Some time ago, I discovered that Mode/PID 2185 could reveal the torque converter lockup status in the Prado transmission but indication of the selected gear eluded me. Over several weeks I had logged reams and reams of data on my laptop but had no joy. A couple of weekends ago, I decided to re-process all of the data I had gathered, comparing the gearbox data against those for the vehicle speed. Finally a pattern emerged. One byte of PID 2185 consistently showed values 01 to 06, always showing the '1' when stopped or at low speeds and the number climbing as speed increased.

    The following data is taken from a log that I took this afternoon. From a standing start at traffic lights, I entered Roe Highway in Malaga, in Perth's north. I planted my foot to get up to 100kmh as quickly as possible. You will see the 4th byte increase from 1 (first gear) to 6 (sixth) as speed increases to 100kmh. This few records of the log can be seen from the 14 minute mark in the graph below.
    14:00.876 7E8 05 61 85 01 00 10 00 00
    14:03.873 7E8 05 61 85 01 00 10 00 00
    14:06.879 7E8 05 61 85 02 00 10 00 00
    14:09.879 7E8 05 61 85 02 20 00 00 00
    14:12.872 7E8 05 61 85 03 20 10 00 00
    14:15.881 7E8 05 61 85 04 20 10 00 00
    14:18.878 7E8 05 61 85 04 20 10 00 00
    14:21.879 7E8 05 61 85 04 20 10 00 00
    14:24.880 7E8 05 61 85 05 20 10 00 00
    14:27.881 7E8 05 61 85 05 20 10 00 00
    14:30.879 7E8 05 61 85 06 20 00 00 00
    14:33.879 7E8 05 61 85 06 20 18 00 00
    14:36.876 7E8 05 61 85 06 A0 18 00 00
    14:39.877 7E8 05 61 85 06 A0 18 00 00
    1. Time stamps are not normally part of the OBDII data - these are added by my interface
    2. 7E8 is the response header address from the main ECU (I send the 2185 PID to address 7E0)
    3. The selected gear number is the 4th byte. Hexadecimal values 1 to 6 match gear numbers
    4. Also of interest is the 5th byte, where the most significant bit indicates torque converter lockup. So a value of 'A0' here shows the torque converter lock is active.
    This chart shows the relationship between speed and gear selection for the entire half-hour journey:

    Click image for larger version  Name:	Gear vs. Speed Chart.JPG Views:	0 Size:	23.0 KB ID:	752613
    What does this mean for owners of Scangauge, Ultragauge, Torque and other OBDII monitor owners? I have studied the Scangauge programming documents and I think the following should work, although I don't know how you would actually display the data.

    Scangauge II
    Gauge: Gear Selected
    TXD: 07E02185
    RXF: 046105850000
    RXD: 2808
    MTH: 000100010000

    I don't fully understand the Ultragauge but the following should be a good start

    Ultragauge MX
    TDATA: 07E02185
    TCTRL: ??
    RCTRL: ??
    RPOS: 1808
    MTCH: 618500 (?)
    X: 0001 /: 0001 +: 0000

    Torque will probably use byte 'A'

    I hope that other enthusiasts can confirm or enhance this config for specific devices.

    Last edited by GeeWhizz; 13-07-2020, 10:56 PM.

  • #2
    well done mate , Its a bit above my head but I do like the fact that you are doing research that can help others.


    • #3
      Hi Peter, thanks for that research.

      For reference the Torque Pro inputs based on your data and confirmed by testing (2018 2.8l 6-speed GXL GDJ150R) are as follows:

      Transmission Gear Lock-up
      PID 2185
      Equation Lookup(BIT(B:7)::0='Off':1='Lock')
      OBD header 7E0

      Transmission Gear Selection
      PID 2185
      Equation A
      OBD header 7E0

      Last edited by Aquanaught; 07-01-2021, 03:06 PM.


      canli bahis siteleri bahis siteleri
      antalya escort
      istanbul escort maltepe escort
      sex vidio
      antalya escort
      gaziantep escort gaziantep escort
      asyabahis maltcasino olabahis olabahis
      ankara escort
      atasehir escort tuzla escort
      replica watches
      sikis sex hatti